Using Sentinel-5P TROPOMI Data for Air Quality Assessment in the City of Oran, Western Algeria

Abstract

With economic development, the emergence of cities, and the growth of transportation, air quality has become a significant concern. This leads to ecological imbalance and threatens the health of millions of people. The city of Oran, due to its importance and economic growth in recent decades, is no exception. The primary objective of this study is to conduct a comprehensive analysis of pollutant trends for the period 2019–2022 and their relationships with surface temperatures. The data for four pollutants from Sentinel-5P, namely ozone (O₃), carbon monoxide (CO), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂), were obtained and processed using the Google Earth Engine (GEE) platform. Given the variability in emissions from year to year, the results from the Air Pollution Index (API) indicate a trend toward moderate to high pollutant concentrations (> 1.54e-2 mol/m²), with the city being the primary source of pollutants. In 2019, 61% of the study area was heavily polluted, with concentrations exceeding 1.54e-2 mol/m². This percentage was 45% in 2020, 58% in 2021, and 44% in 2022, while concentrations below 1.54e-2 mol/m² represented 15%, 26%, 17%, and 30%, respectively. Except for SO₂ (> 40 µg/m³), the levels of NO₂ (~ 10 µg/m³) and CO (< 4 mg/m³) align with the levels recommended by the World Health Organization (WHO). Furthermore, a comparison of the results with surface temperatures shows that, except for O₃, no significant correlation exists. In the context of sustainable development, these findings represent a proactive strategy for understanding pollutant concentrations and formulating effective policies to improve air quality in the city of Oran.